The present invention relates to an initially gas-impermeable laminate capable of delamination into gas-permeable and gas-impermeable portions. More specifically, the invention pertains to packaging for products, such as food products (e.g., fresh red meat or poultry), that are initially enclosed by the gas-impermeable laminate under certain environmental conditions (e.g., a low-oxygen environment). The initial environmental conditions within the package may subsequently be altered by peelably removing the gas-impermeable portion of the laminate from the gas-permeable portion, thereby allowing air to enter the package to effect a desired change in the packaged product.
Historically, large sub-primal cuts of meat have been butchered and packaged in each supermarket. This arrangement has long been recognized to be inefficient and expensive. It would instead be preferable to butcher and package the meat at a central processing facility which benefits from economies of scale, and then ship the packaged meat to individual supermarkets or other retail outlets such as is done, for example, with many poultry products. It is believed that central processing of meat would also lead to a higher quality, more sanitary product with a longer shelf-life than meat which is butchered and packaged in individual supermarkets.
Fresh red meat presents a particular challenge to the concept of centralized processing and packaging due to its oxygen-sensitivity as manifested primarily in the shelf-life and appearance (color) of a packaged meat product. For example, while a low-oxygen packaging environment generally increases the shelf-life of a packaged meat product (relative to meat products packaged in an environment having a higher oxygen content), red meat has a tendency to assume a purple color when packaged in the absence of oxygen or in an environment having a very low oxygen concentration, i.e., below about 1% oxygen. Unfortunately, such a purple color is undesirable to most consumers, and marketing efforts to teach the consumer about the acceptability of the purple color have been largely ineffective. When meat is exposed to a sufficiently high concentration of oxygen, e.g., as found in air, it assumes a bright red color which most consumers associate with freshness. After 1 to 3 days of such exposure, however, meat assumes a brown color which, like the purple color, is undesirable to most consumers (and indicates that the meat is beginning to spoil).
Thus, in order to effectively butcher and package meat products in a central facility for distribution to retail outlets, the meat would desirably be packaged, shipped, and stored in a low-oxygen environment for extended shelf-life, and then displayed for consumer sale in a relatively high-oxygen environment such that the meat is caused to "bloom" (or, more accurately, "re-bloom") into a red color just before being placed in a retail display case. While in the retail display case, the meat product is desirably contained in a package which protects it from microbial and other contamination. In order to attain the maximum economic benefit from centralized packaging, the package in which the meat product is displayed for consumer sale is the same package in which the meat product is initially packaged and shipped from the central processing facility. As can be appreciated, centralized butchering and packaging of fresh red meat presents a number of difficult packaging challenges.
A variety of packages, known as "case-ready packages," have been developed in an effort to overcome the foregoing challenges. One type of case-ready package is a peelable "vacuum-skin" package ("peelable VSP"). A traditional peelable VSP includes a lid formed from a laminate that separates into gas-permeable and gas-impermeable portions and encloses a packaged meat product that is disposed on a support member. The lid is thermoformable, i.e., capable of being formed into a desired shape upon the application of heat, and is thermoformed about the product on the support member by means of heat and differential pressure. In so doing, the lid is also bonded to the support member outside the periphery of the product. Virtually all of the air is evacuated from the interior of the package so that the lid conforms very closely to the contour of the packaged product. (For further details see, e.g., U.S. Pat. No. Re 30,009 (Purdue et al.) and U.S. Pat No. 5,346,735 (Logan et al.), the disclosures of which are hereby incorporated herein by reference). Another type of peelable VSP is used, e.g., for high-profile meat cuts such as beef roasts, and consists of a pouch in which the meat product is contained. The interior of the pouch is evacuated so that it conforms to the contour of the packaged product. The pouch includes an outer, gas-impermeable portion that is peelably removable from an inner, gas-permeable portion to allow the meat product to re-bloom prior to placing the package in a retail display case. Such a package is exemplified in, e.g., U.S. Ser. No. 08/940,673 entitled PACKAGE COMPRISING AN INNER, GAS-PERMEABLE ENCLOSURE AND AN OUTER, GAS-IMPERMEABLE ENCLOSURE PEELABLY ADHERED TO THE INNER ENCLOSURE and filed Sep. 30, 1997, the disclosure of which is hereby incorporated herein by reference.
Similar to a peelable VSP, a peelable "modified-atmosphere" package ("peelable MAP") includes a lid formed from a laminate. The laminate separates into gas-permeable and gas-impermeable portions and encloses a meat product that is disposed within a support member having a peripheral flange to which the lid is secured. Prior to securing the lid to the support member, air is generally evacuated from the interior of the support member and replaced by a gas that extends the shelf life of the packaged product. The gas-impermeable portion of the lid is peelably removed prior to retail display so that the packaged product is displayed in a state of re-bloom. Examples of such packages are disclosed in, e.g., U.S. Pat. No. 5,686,126; U.S. Ser. No. 08/755,990, filed Nov. 25, 1996 and entitled PACKAGE HAVING A DUAL-FILM LID COMPRISING A GAS-IMPERMEABLE FILM AND A DELAMINATABLE, GAS-PERMEABLE FILM; and U.S. Ser. No. 08/764,405, filed Dec. 11, 1996 and entitled LAMINATE HAVING A COEXTRUDED, MULTILAYER FILM WHICH DELAMINATES AND PACKAGE MADE THEREFROM, the disclosures of which are hereby incorporated herein by reference.
While peelable VSP and MAP case-ready packages have been and continue to be successful, there is always a need and desire for improvements. One area of improvement is product labeling. As with any package, peelable VSP and MAP packages must generally contain some sort of labeling thereon that provides certain information to the consumer such as, e.g., product information, pricing, identification of the company from which the packages originated, etc. In order to be clearly visible to the consumer, such labels are placed on the lid because the transparent laminate from which the lid is formed is always facing the consumer in the retail display case so that both the packaged product and label can be inspected without having to move or handle the package.
For the same reasons that it is desirable to package fresh red meat and poultry products at central processing facilities, it would also be desirable for the packages to be labeled with individualized information at the central processing facilities. Currently, however, such labels must be prepared and affixed to the gas-permeable portion of the lid at the retail facility following the removal of the gas-impermeable portion of the lidding laminate. This is necessary because current lidding laminates for peelable VSP and MAP packages do not generally facilitate centralized printing and/or labeling. In the first place, it is not practical to apply the label to the upper, gas-impermeable portion of the lid because this portion is peeled from the packages and discarded prior to placing the packages in the retail display case. Additionally, placement of the printed image or label within the laminate such that it remains on the package after the gas-impermeable portion is removed has not been feasible. Current commercially successful lidding laminates delaminate within a coextruded, multilayer component-film of the laminate (as opposed to delaminating at a film/film interface) such that only a gas-permeable portion of the coextruded film remains on the package after delamination. It would be impossible to interject a label or printed image between two remaining layers of the coextruded film, and concerns of food contamination would prevent a printed image or label from being applied to the underside of the remaining portion of the coextruded film because such image or label could directly contact the packaged food product. Labels or printed indicia applied to the sidewalls or bottom surface of the support tray are not attractive to consumers who are accustomed to seeing labeling on the upper surface of packages.
Thus, while case-ready packages of the type discussed above have obviated the need for in-store butchering, retail workers are still required to create and apply a unique label for each package, as it is presently not feasible for a pre-printed image to be centrally applied to commercially-available lidding laminates such that the image will remain on the package after the gas-impermeable portion of the lid is removed and the package is placed in a retail display case.
Accordingly, a need exists for a case-ready package with a lidding laminate that can carry product information and other indicia that is applied at a central processing and packaging facility but which remains on the package lid after removal of the gas-impermeable portion so that the information is visible to the consumer.